Ethernet LAN designed to run on twisted pair cabling. 10BaseT runs at 10 megabits per second. The maximum length for the cabling between the NIC and the switch is 100 meters. It uses baseband signaling.

100BaseT

Generic term for an Ethernet cabling system designed to run at 100 megabits per second on twisted pair cabling.

1000BaseT

Gigabit Ethernet on UTP.

110 Block

The most common connection used with structured cabling, connecting horizontal cable runs with patch panels.

16-bit (PC Card)

Type of PC card that can have up to two distinct functions or devices, such as a modem/network card combination.

3.5-inch Floppy drive

size of all modern floppy disk drives; the format was introduced in 1986 and is one of the longest surviving pieces of computer hardware

34-pin ribbon cable

Type of cable used by floppy drives

40-pin ribbon cable

PATA cable used to attach EIDE devices (such as hard drives) or ATAPI devices (such as optical drives) to a system

64-bit processing

A type of processing that can run a compatible 64-bit OS and 64-bit applications. 64-bit PCs have a 64-bit-wide address bus, enabling them to use more than 4 GB of RAM.

8.3 naming system

File-naming convention that specified a maximum of eight characters for a filename, followed by a three-character file extension. Has been replaced by LFN (Long filename) support.

80-wire ribbon cable

PATA cable used to attach fast EIDE devices (such as ATA/100 hard drives) or ATAPI devices (such as optical drives) to a system.

802.11a

Wireless networking standard that operations in the 5GHz band with a theoretical maximum throughput of 54 Mbps.

802.11b

Wireless networking standard that operates in the 2.4 GHz band with a theoretical maximum throughput of 11 Mbps.

802.11g

Wireless networking standard that operates in the 2.4 GHz band with a theoretical maximum throughput of 54 Mbps and is backwards compatible with 802.11b

802.11n

Wireless networking standard that can operate in both the 2.4 GHz and 5 GHz bands and use multiple in/multiple out (MIMO) to achieve a theoretical maximum throughput of 100+ Mbps.

AC'97

Sound card standard for lower-end audio devices; created when most folks listened to stereo sound at best

Accelerometer

Feature in smartphones and tablets that rotates the screen when the device is physically rotated.

Advanced Configuration and Power Interface: Power management specification that far surpasses it predecessor, APM, by providing support for hot-swappable devices and better control of power modes.

Action Center

A one-page aggregation of event messages, warnings, and maintenance messages in Windows 7.

Active Matrix

Type of LCD that replaced the passive matrix technology used in most portable computer displays. Also called TFT (thin film transistor).

Active Partition

On a hard drive, primary partition that contains an operating system

Active PFC (Power Factor Correction)

Circuitry built into PC power supplies to reduce harmonics.

Activity Light

An LED on a NIC, Hub or switch that blinks rapidly to show data transfers over the network.

ad hoc mode

Decentralized wireless mode, otherwise known as peer-to-peer mode, where each wireless node is in meshed contact with every other node.

Address Bus

Set of wires leading from the CPU to the memory controller chip (traditionally called the Northbridge) that enables the CPU to address RAM. Also used by the CPU for I/O addressing. On current CPUs with built-in memory controllers, the address bus refers to the internal electronic channel from the microprocessor to RAM, alond which the addresses of memory storage locations are transmitted. Like a PO Box, each memory location has a distinct number or address; the address bus provides the means by which the microprocessor can access every location in memory.

Address Space

Total amount of memory addresses that an address bus can contain

administrative shares

Administrator tool to give local admins access to hard drives and system root folders

Administrative tools

Group of Control Panel applets, including Computer Management, Event Viewer, and Reliability and Performance Monitor.

ADSL

Asymmetric digital subscriber line: Fully digital, dedicated connection to the telephone system that provides average download speeds of 7 Mbps and upload speeds of 512 Kbps.

AES

Advanced Encryption Standard: A block cipher created in the late 1990s that uses a 128-bit block size and 128-,192, or 256-bit key size. Practically uncrackable.

Advanced Startup Options Menu

Menu that can be reached during the boot process that offers advanced OS startup options, such as to boot to Safe Mode or boot into Last Known Good Configuration.

Adware

Type of malicious program that downloads ads to a user's computer, generating undesirable network traffic.

Advanced Micro Devices: CPU and chipset manufacturer that competes with Intel. Produces the popular Phenom, Ahtlon, Sempron, Turion, and Duron microprocessors; also produces video card processors under its ATI brand.

AMI

American Megatrends, Inc.: Major producer of BIOS software for motherboards, as well as many other computer-related components and software.

Amperes

Unit of measure for amperage, or electrical current

Amplitude

Loudness of a sound card

AMR

Audio Modem Riser: Proprietary slot used on some motherboards to provide a sound interference-free connection for modems, sound cards, and NICs.

Analog

Device that uses a physical quantity, such as length or voltage, to represent the value of a number. By contrast, digital storage relies on a coding system of numeric units.

Anti-aliasing

In computer imaging, blending effect that smooths sharp contrast between two regions-e.g., jagged lines or different colors. Reduces jagged edges of text or objects. In voice signal processing, process of removing or smoothing out spurious frequencies from waveforms produced by converting digital signals back to analog.

API

Application programming interface: Software definition that describes OS calls for application software; conventions defining how a service is invoked.

APIPA

Automatic Private Internet Protocol Addressing: Feature of Windows that automatically assigns an IP address to the system when the client cannot obtain an IP address automatically.

APM

Advanced Power Management: BIOS routines that enable the CPU to turn on and off selected peripherals

ARP

Address Resolution Protocol: Protocol in the TCP/IP suite used with the command-line utility of the same name (arp) to determine the MAC address that corresponds to a particular IP address.

ASCII

American Standard Code for Information Interchange: Industry-standard 8-bit characters used to define text characters, consisting of 96 upper- and lowercase letters, plus 32 nonprinting control characters, each of which is numbered. These numbers were designed to achieve uniformity among computer devices for printing and exchange of simple text documents.

Aspect Ratio

Ratio of width to height of an object. Standard television has a 4:3 aspect ratio

ASR

Automated System Recovery: Windows XP tool designed to recover a badly corrupted Windows system; similar to the ERD in Windows 2000.

AT

Advanced Technology: Model name of the second generation, 80286-based IBM computer. Many aspects of the AT, such as BIOS, CMOS, and expansion bus, have become de facto standards in the PC industry. The physical organization of the components on the motherboard is called the AT form factor.

ATA

AT Attachment: Type of hard drive and controller designed to replace the earlier ST506 and ESDI drives without requiring replacement of the AT Bios-hence, AT attachment. These drives are more popularly known as IDE drives. The ATA/33 standard has drive transfer speeds up to 33 MBps; the ATA/66 up to 66 MBps; the ATA/100 up to 100 MBps; and the ATA/133 up to 133 MBps.

ATA/ATAPI-6

Also known as ATA-6 or "Big Drive." Replaced the INT13 extensions and allowed for hard drives as large as 144 petabytes (144 million GB).

ATAPI

ATA Packet Interface: Series of standards that enables mass storage devices other than hard drives to use the IDE/ATA controllers. Popular with optical drives.

ATAPI-compliant

Devices that utilize the ATAPI standard.

attrib.exe

Command used to view the specific properties of a file; can also be used to modify or remove file properties, such as read-only, system, or archive.

attributes

Values in a file that determine the hidden, read-only, system, and archive status of the file.

ATX

Advanced Technology Extended: Popular motherboard form factor that generally replaced the AT form factor.

Any method a computer uses to determine what an authenticated user can do.

Autodetection

Process through which new disks are automatically recognized by the BIOS

Automatic Private IP Addressing

APIPA: A networking feature of OS's that enables DHCP clients to self-configure an IP address and subnet mask automatically when a DHCP server isn't available.

autorun.inf

File included on some media that automatically launches a program or installation routine when the media is inserted/attached to a system.

autosensing

Used by better-quality sound cards to detect a device plugged into a port and to adapt the features of that port

auto-switching power supply

Type of power supply able to detect the voltage of a particular outlet and adjust accordingly.

Award Software

Major brand of BIOS software for motherboards. Owned by Phoenix Technologies

Backside Bus

Set of wires that connects the CPU to Level 2 cache. First appearing in the Pentium Pro, all modern CPUs have a backside bus. Some buses run at full speed of the CPU, whereas others run at a fraction. Earlier Pentium IIs, for example, had backside buses running at half the speed of the processor.

Backup and Restore Center

Windows Vista/7's backup utility (Windows 7 drops "Center" from the name). It offers two options: create a backup or restore from a back up.

Backup or Restore Wizard

Utility contained within Windows that allows users to create system backups and set system restore points

Backup Utility

ntbackup: Windows XP's tool for creating and restoring backups.

Bandwidth

Piece of the spectrum occupied by some form of signal, such as television, voice, or fax data. Signals require a certain size and location of bandwidth to be transmitted. The higher the bandwidth, the faster the signal transmission, allowing for a more complex signal such as audio or video. Because bandwidth is a limited space, when one user is occupying it, others must wait their turn. Bandwidth is also the capacity of a network to transmit a given amount of data during a given period.

bank

Total number of SIMMs or DIMMs that can be accessed simultaneously by the chipset. The "width" of the external data bus divided by the "width" of the SIMM or DIMM sticks. DIMM slots that must be populated to activate dual or triple-channel memory.

basic disk

Hard drive partitioned in the "classic" way with a master boot record (MBR) and partition table.

baud

One analog cycle on a telephone line. In the early days of telephone data transmission, the baud rate was often analogous to bits per second. Due to advanced modulation of baud cycles as well as data compression, this is no longer true.

bcdedit

A command-line tool that enables you to view the BCD store, which lists the Windows boot options.

beep codes

Series of audible tones produced by a motherboard during the POST. These tones identify whether the POST has completed successfully or whether some piece of system hardware is not working properly. Consult the manual for your particular motherboard for a specific list of beep codes.

binary numbers

Number system with a base of 2, unlike the number systems most of us use that have bases of 10 (decimal numbers), 12 (measurement in feet and inches), and 60 (time). Binary numbers are preferred for computers for precision and economy. An electronic circuit that can detect the difference between two states (on-off, 0-1) is easier and more inexpensive to build than one that could detect the differences among ten states (0-9).

biometric device

Hardware device used to support authentication; works by scanning and remembering a unique aspect of a user's various body parts by using some form of sensing device such as a retinal scanner.

BIOS

Basic Input/Output Services: Classically, software routines burned onto the system ROM of a PC. More commonly seen as any software that directly controls a particular piece of hardware. A set of programs encoded in read-only memory on computers. These programs handle startup operations and low-level control of hardware such as disk drives, the keyboard, and monitor.

bit

Single binary digit. Also, any device that can be in an on or off state.

bit depth

Number of colors a video is capable of producing. Common bit depths are 16-bit and 32-bit, representing 65,536 colors and 16.7 million colors (plus an 8-bit alpha channel for transparency levels), respectively.

BitLocker Drive Encryption

Drive encryption software offered in Windows Vista/7 Ultimate and Enterprise editions. BitLocker requires a special chip to validate hardware status and to ensure that the computer hasn't been hacked.

Blu-ray Disc

Optical disc format that stores 25 and 50 GB of data, designed to be the replacement media for DVD.

Boot

To initiate an automatic routine that clears the memory, loads the operating system, and prepares the computer for use. Term derived from "pull yourself up by your bootstraps." PCs must do that because RAM doesn't retain program instructions when power is turned off. A cold boot occurs when the PC is physically switched on. A warm boot loads a fresh OS without turning off the computer, lessening the strain on the electronic circuitry. To do a warm boot, press the CTRL-ALT-DELETE keys twice in rapid succession (the three fingered salute).

Boot Configuration Data File

BCD: File that contains information about the various operating systems installed on the system as well as instructions for how to actually load them.

Boot Sector

First sector on a PC hard drive or floppy disk, track 0. The boot-up software in ROM tells the computer to load whatever program is found there. If a system disk is read, the program in the boot record directs the computer to the root directory to load the operating system.

boot.ini

Text file used during the boot process that provides a list of all OS's currently installed and available for ntldr. Also tells where each OS is located on the system. Used in Windows XP and earlier Microsoft operating systems.

bootable disk

Disk that contains a functional OS; can also be a floppy disk, USB thumb drive, or optical disc.

bootmgr

Windows Vista/7's Boot Manager

bootrec

A Windows Recovery Environment troubleshooting and repair tool that repairs the MBR, boot sector, or BCD store. It replaces the fixboot and fixmbr Recovery Console commands used in Windows XP and earlier OSs.

bootstrap loader

Segment of code in a system's BIOS that scans for an OS, looks specifically for a valid boot sector, and, when one is found, hands control over to the boot sector; then the bootstrap loader removes itself from memory.

bps

bits per second: Measurement of how fast data is moved from one place to another. A 56K modem can move ~56,000 bits per second.

bridge

A device that connects two networks and passes traffic between them based only on the node address, so that traffic between nodes on one network does not appear on the other network. For example, an Ethernet bridge only looks at the MAC address. Bridge filter and forward packets based on MAC addresses and operate at Level 2 (Data Link layer) of the OSI seven-layer model.

BTX

Balanced Technology Extended: Motherboard form factor designed as an improvement over ATX

buffer underrun

Inability of a source device to provide a CD burner with a constant stream of data while burning a CD-R or CD-RW

buffered/registered DRAM

Usually seen in motherboards supporting more than four sticks of RAM, required to address interference issues caused by the additional sticks.

bug

Programming error that causes a program or a computer system to perform erratically, produce incorrect results, or crash.

bus

Series of wires connecting two or more separate electronic devices, enabling those devices to communicate. Also, a network topology where computers all connect to a main line called a bus cable.

Unit of 8 bits; fundamental data unit of PCs. Storing the equivalent of one character, the byte is also the basic unit of measurement for computer storage.

CAB files

Short for cabinet files. These files are compressed and most commonly used during OS installation to store many smaller files, such as device drivers.

Cache (disk)

Special area of RAM that stores the data most frequently accessed from the hard drive. Cache memory can optimize the use of your systems.

cache (L1, L2, L3, etc.)

Special section of fast memory, usually built into the CPU, used by the on-board logic to store information most frequently accessed by the CPU.

Capacitive touchscreen

Type of touchscreen that uses electrical current in your body to determine movement of your fingers across the screen.

CardBus

32-bit PC cards that can support up to eight devices on each card. Electrically incompatible with earlier PC cards.

CAT 5

Category 5 wire; TIA/EIA standard for UTP wiring that can operate at up to 100 Mb/s.

CAT 5e

Category 5e wire; TIA/EIA standard for UTP wiring that can operate at up to 1 Gb/s

CAT 6

Category 6 wire; TIA/EIA standard for UTP wiring that can operate at up to 10 Gb/s.

CAT 6a

Category 6a wire; augmented CAT 6 UTP wiring that supports 10GBaseT networks at the full 100 meter distance between a node and a switch.

Catastrophic failure

Describes a failure in which a component or whole system will not boot; usually related to a manufacturing defect of a component. Could also be caused by overheating and physical damage to computer components.

CCFL

Cold Cathode Fluorescent Lamp: Light technology used in LCDs and flatbed scanners. CCFLs use relatively little power for the amount of light they provide.

cd (chdir)

Shorthand for "change directory". Allows you to change the focus of the command prompt from one directory to another.

CD Quality

Audio quality that has a sample rate of 44.4 Khz and bit rate of 128 bits.

CDDA

CD-Digital Audio: Special format used for early CD-ROMs and all audio CDs; divides data into variable length tracks. A good format to use for audio tracks but terrible for data because of lack of error checking.

Centronics Connector

Connector used with older printers.

CCNA

Cisco Certified Network Associate: On of the certifications demonstrating a knowledge of Cisco networking products.

CHAP

Challenge Handshake Authentication Protocol: Common remote access protocol; the serving system challenges the remote client, usually by means of asking for a password.

Chipset

Electronic chips, specifically designed to work together, that handle all of the low-level functions of a PC. In the original PC, the chipset consisted of close to 30 different chips; today, chipsets usually consist of one, two, or three separate chips imbedded into a motherboard.

chkdsk

Checkdisk: Hard drive error detection and, to a certain extent, correction utility in Windows. Originally a DOS command (chkdsk.exe); also the executable for the graphical Error-checking tool.

clock cycle

Single charge to the clock wire of a CPU

clock-multiplying CPU

CPU that takes the incoming clock signal and multiplies it inside the CPU to let the internal circuitry of the CPU run faster.

Clock speed

Speed at which a CPU executes instructions. Measured in MHz or GHz.

Clock (clk) wire

A special wire that, when charged, tells the CPU that another piece of information is waiting to be processed.

Closed source

Software that is solely controlled by its creator or distributor.

cluster

Basic unit of storage on a floppy or hard disk. Multiple sectors are contained in a cluster. When Windows stores a file on a disk, it writes those files into dozens or even hundreds of contiguous clusters. If there aren't enough contiguous open clusters available, the OS finds the next open cluster and writes there, continuing this process until the entire file is saved. The FAT or MFT tracks how the files are distributed among the clusters on the disk.

CMOS

Complementary Metal-oxide Semiconductor: Originally, the type of nonvolatile RAM that held information about the most basic parts of your PC, such as hard drives, floppies, and amount of DRAM. Today. actual CMOS chips have been replaced by flash-type nonvolatile RAM. The information is the same, however, and is still called CMOS-even though it is now almost always stored on Flash RAM.

CMOS setup program

Program enabling you to access and update CMOS data.

CNR

Communications and networking riser: Proprietary slot used on some motherboards to provide a sound interference-free connection for modems, sound cards, and NICs.

Code

Set of symbols representing characters or instructions in a computer program.

A request, typed from a terminal or embedded in a file, to perform an operation or to execute a particular program.

command-line interface

User interface for an OS devoid of all graphical trappings

Command prompt

Text prompt for entering commands.

CompTIA

Computer Technology Industry Association

Computer Management

Applet in Windows' Administrative Tools that contains several useful snap-ins, such as Device Manager and Disk Management.

Computing Process

Four parts of a computer's operation: Input, processing, output, and storage.

Conditioning charger

Battery charger that contains intelligent circuitry that prevents portable computer batteries from being overcharged and damaged.

Connectors

Small receptacles used to attach cables to a system.

Container file

File containing two or more separate, compressed tracks, typically an audio track and a moving-picture track. Also known as a wrapper.

context menu

Small menu brought up by right-clicking on objects in Windows

Controller card

Card adapter that connects devices, such as a disk drive, to the main computer bus/motherboard.

Convergence

Measure of how sharply a single pixel appears on a CRT; a monitor with poor convergence produces images that are not sharply defined.

copy backup

Type of backup similar to a normal or full backup, in that all selected files on a system are backed up. This type of backup does not change the archive bit of the files being backed up.

Copy command

Command in the command-line interface for making a copy of a file and pasting it in another location.

Counter

Used to track data about a particular object when using the Performance Console in Windows XP

CPU

Central Processing Unit: "Brain" of the computer. Microprocessor that handles primary calculations for the computer.

CRC

Cycle Redundancy Check: Very accurate mathematical method used to check for errors in long streams of transmitted data. Before data is sent, the main computer uses the data to calculate a CRC value from the data's contents. If the receiver calculates from the received data a different CRC value, the data was corrupted during transmission and is resent. Ethernet packets use the CRC algorithm in the FCS portion of the frame.

CRIMM

Continuity RIMM: Passive device added to populate unused banks in a system that uses Rambus RIMMs.

CrossFire

Technology that combines the power of multiple AMD graphics cards in a system.

CRT

Cathode Ray Tube: Tube of a monitor in which rays of electrons are beamed onto a phosphorescent screen to produce images. Also, a shorthand way to describe a monitor that uses CRT rather than LCD technology.

Single track on all the platters in a hard drive. Imagine a hard drive as a series of metal cans, nested one inside another; single can would represent a cylinder.

daily backup

Backup of all files that have been changed on that day without changing the archive bits of those files.

Daisy-chaining

Method of connecting several devices along a bus and managing the signals for each device.

Data Classification

System of organizing data according to its sensitivity. Common classifications include public, highly confidential, and top secret.

Data structure

Scheme that directs how an OS stores and retrieves data on and off a drive. Used interchangeably with the term file system.

DB connectors

D-shaped connectors used for a variety of connections in the PC and networking world. Can be male or female and have varying number of pins or sockets. Also called D-sub, D-subminiature, or D-shell connectors.

DDR SDRAM

Double data rate SDRAM: Type of DRAM that makes two processes for every clock cycle.

DDR2

Type of SDRAM that sends 4 bits of data in every clock cycle.

DDR3 SDRAM

Type of SDRAM that transfers data at twice the rate of DDR2 SDRAM.

decibels

Unit of measurement typically associated with sound. The higher the number of decibels, the louder the sound.

default gateway

In a TCP/IP network, the nearest router to a particular host. This router's IP address is part of the necessary TCP/IP configuration for communicating with multiple networks using IP.

definition file

List of virus signatures that an antivirus program can recognize.

defrag

defragmentation: Procedure in which all the files on a hard disk are rewritten on disk so that all parts of each file reside in contiguous clusters. The result is an improvement in disk speed during operations.

degauss

Procedure used to break up the electromagnetic fields that can build up on the cathode ray tube of a monitor; involves running a current through a wire loop. Most monitors feature a manual degaussing tool.

DHCP

Dynamic Host Configuration Protocol: Protocol that enables a DHCP server to set TCP/IP settings automatically for a DHCP client.

differential backup

Similar to an incremental backup. Backs up the files that have been changed since the last backup. This type of backup does not change the state of the archive bit.

digital certificate

Form in which a public key is sent from a Web server to a Web browser so that the browser can decrypt the data sent by the server.

DLNA

Digital Living Network Alliance: Device that connect to a home network, discover each other, and share media. In theory, DLNA devices should work with minimal setup or fuss, even if sourced from different manufacturers.

DIMM

Dual Inline Memory Module: 32 or 64-bit type of DRAM packaging, similar to SIMMs, with the distinction that each side of each tab inserted into the system performs a separate function. DIMMs come in a variety of sizes, with 184- and 240-pin being the most common on desktop computers.

DirectX

Set of APIs enabling programs to control multimedia, such as sound, video, and graphics. Used in Windows Vista/7 to draw the Aero desktop.

Disk Cleanup

Utility built into Windows that can help users clean up their disks by removing temporary Internet files, deleting unused program files, and more.

disk cloning

Taking a PC and making a duplicate of the hard drive, including all data, software, and configuration files, and transferring it to another PC.

disk duplexing

Type of disk mirroring using two separate controllers rather than one; faster than traditional mirroring.

disk initialization

A process that places special information on every hard drive installed in a Windows syste,.

Disk Management

Snap-in available with Microsoft Management Console that enable techs to configure the various disks installed in a system.

Disk Mirroring

Process by which data is written simultaneously to two or more disk drives. Read and write speed is decreased but redundancy in case of catastrophe is increased.

Process by which data is spread among multiple drives. Increases speed for both reads and writes of data. Considered RAID level 0 because it does not provide fault tolerance.

disk striping with parity

Method for providing fault tolerance by writing data across multiple drives and then including an additional drive, called a parity drive, that stores information to rebuild the data contained on the other drives. Requires at least three physical disks; two for the data and a third for the parity drive. This provides data redundancy at RAID levels 3-5 with different options.

disk thrashing

Hard drive that is constantly being accessed due to lack of available system memory. When system memory runs low, a Windows system will utilize hard disk space as "virtual" memory, thus causing and unusual amount of hard drive access.

diskpart

A fully functioning command-line partitioning tool.

display adapter

Handles all the communication between the CPU and the monitor. Also known as a video card.

Display applet

Tool in Windows XP and 7 used to adjust display settings, including resolution, refresh rate, driver information, and color depth.

Display port

Digital video connector used by Apple Mac desktop models and some PCs, notable from Dell. Designed by VESA as a royalty-free connector to replace VGA and DVI.

DMA

Direct Memory Access: Technique that some PC hardware devices use to transfer data to and from the memory without using the CPU.

DMA controller

Resides between the RAM and the devices and handles DMA requests

DNS

Domain Name Service: TCP/IP name resolution system that translates a host name into and IP address.

DNS Domain

Specific branch of the DNS name space. First-level DNS domains include .com, .gov, and .edu.

domain

Groupings of users, computers, or networks. In Microsoft Networking, a domain is a group of computers and users that share a common account database and a common security policy. On the internet, a domain is a group of computers that share a common element in the hierarchical name.

domain-based network

Network that eliminates the need for logging on to multiple services by using domain controllers to hold the security database for all systems.

DOS

Disk Operating System: First popular OS available for PCs. A text-based, single-tasking OS that was not completely replaced until the introduction of Windows 95

dot-matrix printer

Printer that creates each character from an array of dots. Pin striking a ribbon against the paper, one pin for each dot position, form the dots. May be a serial printer (printing one character at a time) or a line printer.

dot pitch

Value relating to CRTs, showing the diagonal distance between phosphors measured in millimeters.

double-side RAM

RAM stick with RAM chips solder to both sides of the stick. May only by used with motherboards designed to accept double-sided RAM. Very common.

DPMS

Display Power-Management Signaling: Specification that can reduce CRT power consumption by 75% by reducing/eliminating video signals during idle periods.

DRAM

Dynamic Random Access Memory: Memory used to store data in most personal computers. DRAM stores each bit in a "cell" compose of a transistor and a capacitor. Because the capacitor in a DRAM cell can only hold a charge for a milliseconds, DRAM must be continually refreshed, or rewritten, to retain its data.

DriveLock

CMOS program enabling you to control ATA security mode feature set.

DSL

Digital Subscriber Line: High-speed internet connection technology that uses a regular telephone line for connectivity. DSL comes in several varieties, including ADSL, SDSL and many speeds. Typical home-user DSL connections are ADSL with a download speed of 7 Mbps and an upload speed of 512 Kbps.

dual-channel memory

Form of DDR, DDR2, and DDR3 memory access used by many motherboards that requires two identical sticks of RAM.

dual-core

CPUs that have two execution units on the same physical chip but share caches and RAM.

dual-scan passive matrix

Manufacturing technique for increasing display updates by refreshing two lines at a time.

DualView

Microsoft feature enabling Windows to use two or more monitors simultaneously.

DUN

Dial-Up Networking: Software used by Widows to govern the connection between the modem and the ISP

Duplexing

Similar to mirroring in that data is written to and read from two physical drives, for fault tolerance. Separate controllers are used for each drive, both for additional fault tolerance and for additional speed. Considered RAID level 1.

Printer that uses a roll of heat-sensitive plastic file embedded with dyes, which are vaporized and then solidified onto specially coated paper to create a high-quality image.

dynamic disks

Special feature of Windows that enables users to span a single volume across two or more drives. Dynamic disks do not have partitions; they have volumes. Dynamic disks can be striped, mirrored, and striped or mirrored with parity.

The voltage differential between any two objects, one of which is frequently ground or earth, resulting in a degree of attraction for the electrons to move from one of the objects to the other. A large difference between a person and a doorknob, for example, can lead to a shocking experience when the two touch.

EMI

Electromagnetic Interference: Electrical interference from one device to another, resulting in poor performance of the device being interfered with.

ESD

Electrostatic Discharge: Uncontrolled rush of electrons from one object to another. A real menace to PCs, as it can cause permanent damage to semiconductors.

ERD

Emergency Repair Disk: Saves critical boot files and partition information and is the main tool for fixing boot problems in Windows 2000.

emulator

Software or hardware that converts the commands to and from the host machine into an entirely different platform.

encryption

Making data unreadable by those who do not possess a key or password.

equipment rack

A metal structure used in equipment rooms to secure network hardware devices and patch panels. Most racks are 19 inches wide. Devices designed to fit in such a rack use a height measurement called units, or simply U.

erase lamp

Component inside laser printers that uses light to make the coating of the photosensitive drum conductive.

Error-checking

Windows graphical tool that scans and fixes hard drive problems. Often referred to by the name of the executable, chkdsk, or Check Disk.

Process used when person assigned to repair a problem is not able to get the job done, such as sending the problem to someone with more expertise.

Ethernet

Name coined by Xerox for the first standard of network cabling and protocols. Based on a bus topology.

Ethic of Reciprocity

Golden Rule: Do unto others as you would have them do unto you.

EULA

End User License Agreement

Event Auditing

Feature of Event Viewer's Security section that creates an entry in the Security Log when certain events happen, such as a user logging on.

Event Viewer

Utility made available as an MMC snap-in that enables users to monitor various system events, including network bandwidth usage and CPU utilization.

Expand

Command-line utility included with Windows used to access files within CAB files.

expansion bus

Set of wires going to the CPU, governed by the expansion bus crystal, directly connected to expansion slots of varying types.

expansion bus crystal

Controls the speed of the expansion bus

Expansion Slots

Connectors on a motherboard that enable users to add optional components to a system.

ExpressCard

The high-performance serial version of the PC Card that replaced PC Card slots on laptop PCs over the past decade. ExpressCard comes in two widths: 34 mm and 54 mm.

Extended partition

Type of nonbootable hard disk partition. May only have one extended partition per disk. Purpose is to divide a large disk into smaller partitions, each with a separate drive letter.

EAP

Extensible Authentication Protocol: Authentication wrapper that EAP-compliant applications can use to accept one of many types of authentication. While EAP is a general-purpose authentication wrapper, its only substantial use is in wireless networks.

Extension

Two, three, four, five or more letters that follow a filename and identify the type of file. Common file extensions are .zip, .exe, .doc, .java, and .xhtml.

EDB

External Data Bus: Primary data highway of all computers. Everything in your computer is tied either directly or indirectly to the external data bus.

Fast User Switching

Account option that is useful when multiple users share a system; allows users to switch without logging off.

FAT

File Allocation Table: Hidden table that records how files on a hard disk are stored in distinct clusters; the only way DOS knows where to access files. Address of first cluster of a file is stored in the directory file. FAT entry for the first cluster is the address of the second cluster used to store that file. In the entry for the second cluster for the file is the address for the third cluster, and so on until the final cluster, which gets a special "end-of-file" code. There are two FATs, mirror images of each other, in case one is destroyed or damaged. Also refers to the 16-bit file allocation table when used by Windows 2000 and later NT-based OS.

FAT16

File allocation table that uses 16 bits for addressing clusters. Used as the primary hard drive format on DOS and early Windows 95 machines; currently used with smaller capacity flash media devices.

FAT32

File allocation table that uses 32-bit for addressing clusters. Commonly used with Windows 98 and Windows Me systems. Some Windows 2000 Professional and Windows XP systems also use FAT32, although most modern Windows systems use the more robust NTFS. Default format for flash media devices larger than 2 GB.

FAT64

exFAT: A Microsoft-proprietary file system that breaks the 4-GB file-size barrier, supporting files up to 16 exabytes and a theoretical partition limit of 64-zettabytes. Envisioned for use with flash media devices with a capacity exceeding 2 TB.

FCS

Frame Check Sequence: Portion of an Ethernet frame used for error checking, most commonly with the CRC algorithm.

FDISK

Disk-partitioning utility used in DOS and Windows 9x systems.

fiber-optic cable

High-speed cable for transmitting data, made of high-purity glass sealed within an opaque tube.

file

Collection of any form of data that is stored beyond the time of execution of a single job. A file may contain program instructions or data, which may be numerical, textual, or graphical information.

file allocation unit

Another term for cluster.

file assocation

Windows term for the proper program to open a particular file; for example, the file association for opening .MP3 files might be Winamp.

file format

How information is encoded in a file. Two primary types are binary (pictures) and ASCII (text), but within those are many formats, such as BMP and GIF for pictures. Commonly represented by a suffix at the end of the filename; for example, .txt for a text file or .exe for an executable.

file server

Computer designated to store software, courseware, administrative tools, and other data on a LAN or WAN. It "serves" this information to other computers via the network when users enter their personal access codes.

file system

Scheme that directs how an OS stores and retrieves data on and off a drive; FAT32 and NTFS are both file systems. Used interchangeably with the term "data structure"

filename

Name assigned to a file when the file is a first written on a disk. Every file on a disk within the same folder must have a unique name. Filenames can contain any character except the following: /:*?"<>|

Files and Settings Transfer Wizard

Windows XP's system for moving files and settings to a new PC

firewall

Device that restricts traffic between a local network and the Internet.

FireWire

IEEE 1394: Interconnection standard to send wide-band signals over a serialized, physically thin connector system. Serial bus developed by Apple and TI; enables connection of 63 devices at speeds up to 800 megabits per second.

firmware

Embedded programs or code stored on a ROM chip. Generally OS-independent, thus allowing devices to operate in a wide variety of circumstances without direct OS support. The system BIOS is firmware.

Flash ROM

ROM technology that can be electrically reprogrammed while still in the PC. Overwhelmingly the most common storage medium of BIOS in PCs today, as it can be upgraded without a need to open the computer on most systems.

FlexATX

Motherboard form factor. Motherboards built in accordance with the FlexATX form factor are very small, much smaller than microATX motherboards.

Flip 3D

In the Aero desktop environment, a three-dimensional replacecment for ALT-TAB. Accessed by pressing the WINDOWS KEY-TAB key combination.

FPU

Floating point unit: Formal term for math coprocessor circuity inside a CPU. A math coprocessor calculates by using a floating point math. Special CPU circuitry that handles complex numbers.

Floppy Disk

Removable storage media that can hold between 720 KB and 1.44 MB of data.

floppy drive

System hardware that uses removable 3.5 inch disks as storage media.

flux reversal

Point at which a read/write head detects a change in magnetic polarity.

FM synthesis

Producing sound by electronic emulation of various instruments to more-or-less produce music and other sound effects.

Folders List

A tree menu in Windows Explorer for Windows 2000 and XP that displays the file structure on the left side of the window; toggled on with the Folders button. In Windows Vista and 7, the Folders list is active by default.

form factor

Standard for the physical organization of motherboard components and motherboard size. Most common form factors are ATX and BTX

format command

Command in the command-line interface used to format a storage device

formatting

Magnetically mapping a disk to provide a structure for storing data; can be done to any type of disk, including a floppy disk, hard disk, or other type of removable disk.

fragmentation

Occurs when files and directories get jumbled on a fixed disk and are no longer contiguous. Can significantly slow down hard drive access times and can be repaired by using the defrag utility included with each version Windows.

Frame

A data unit transferred across a network. Frames consist of several parts, such as the sending and receiving MAC addresses, the data being sent, and the frame check sequence.

freeware

Software that is distributed for free, with no license fee.

Frequency

Measure of a sound's tone, either high or low.

frontside bus

Wires that connect the CPU to the main system RAM. Generally running at speeds of 66-133 MHz. Distinct from expansion bus and backside bus, though it shares wires with the former.

FTP

File Transfer Protocol: Rules that enable two computers to talk to one another during a file transfer. Protocol used when you transfer a file from one computer to another across the Internet. FTP uses port numbers 20 and 21.

Fuel Cells

Power source that uses chemical reactions to produce electricity. Lightweight, compact, and stable devices expected to replace batteries as the primary power source for portable PCs.

full-duplex

Any device that can send and receive data simultaneously

Full-Speed USB

USB standard that runs at 12 Mbps

Fuser Assembly

Mechanism in laser printers that uses two rollers to fuse toner to paper during the print process.

gain

Ration of increase of radio frequency output provided by antenna, measured in decibels (dB).

GDI

Graphical Device Interface: Component of Windows that utilizes the CPU rather than the printer to process a print job as a bitmapped image of each page.

GPF

General Protection Fault: Error code usually seen when separate active programs conflict on resources or data.

Feature in cellular phones that enables the cell phone companies and government agencies to use the ID or MAC address to pinpoint where your phone is at any given time.

giga

Prefix for the quantity 1,073,741,824 (2^30) or for 1 billion. On gigabyte would be 1,073,741,824 bytes, except with hard drive labeling, where it means 1 billion bytes. One gigahertz is 1 billion hertz.

GPS

Global Positioning System: Technology that enables a mobile device to determine where you are on a map.

GUID GPT

Globally unique identifier partition table: Partitioning scheme that enables you to create more than four primary partitions without needing to use dynamic disks.

GPU

Graphics Processing Unit: Specialized processor that helps the CPU by taking over all of the 3-D rendering duties.

Grayscale Depth

Number that defines how many shades of gray the scanner can save per dot.

grayware

Program that intrudes into a user's computer experience without damaging any systems or data.

Group

Collection of user accounts that share the same access capabilities.

Group Policy

Means of easily controlling the settings of multiple network clients with policies such as setting minimum password lengths or preventing Registry edits.

GUI

Graphical User Interface: Interface that enables user to interact with computer graphically, by using a mouse or other pointing device to manipulate icons that represent programs or documents, instead of using only text as in text as in early interfaces.

Gyroscope

Device that can detect the position of the table or phone in 3-D space.

HAL

Hardware abstraction layer: Part of the Windows OS that separates system-specific devices drivers from the rest of the NT system.

handshaking

Procedure performed by modems, terminals, and computers to verify that communication has been correctly established.

hang

When a computer freezes and does not respond to keyboard commands, it is said to "hang" or to have "hung".

hang time

Number of seconds a too-often-hung computer is airborne after you have thrown it out a second-story window.

hard drive

Data-recording system using solid disks of magnetic material turning at high speeds to store and retrieve programs and data in a computer.

hardware

Physical computer equipment such as electrical, electronic, magnetic, and mechanical drives. Anything in the computer world that you can hold in your hand.

Hardware profile

Feature in Windows XP that enables the user to switch several hardware configurations at once during the Windows boot process.

Hardware protocol

Defines many aspects of a network, from the packet type to the cabling and connectors used.

HBA

Host Bus Adapter: Connects SATA devices to the expansion bus.

HDA

High Definition Audio: Intel-designed standard to support features such as true surround sound with many discrete speakers.

HDMI

High Definition Multimedia Interface: Single multimedia connection that includes both HD video and audio. One of the best connections for outputting to television. Also contains copy protection.

Head actuator

Mechanism for moving the arms inside a hard drive on which the read/write heads are mounted.

heads

Short for read/write heads used by hard drives to store data

hex

Hexadecimal: Base-16 numbering system using ten digits and six letters. In the computer world, shorthand way to write binary numbers by substituting one hex number digit for a four-digit binary number

Hi-Speed USB

USB standard that runs at 480 Mbps. Also referred to as USB 2.0.

horizontal cabling

Cabling that connects the equipment room to the work areas.

host

On a TCP/IP network, single device that has an IP address-any device that can be the source or destination of a data packet. In the mainframe world, computer that is made available for use by multiple people simultaneously.

hot-swappable

Any hardware that may be attached to or removed from a PC without interrupting the PC's normal processing.

HRR

Horizontal Refresh Rate: Amount of time it takes for a CRT to draw one horizontal line of pixels on a display.

HTML

Hypertext Markup Language: ASCII-based, script-like language for creating hypertext documents such as a those on the www.

HTTP over Secure Sockets Layer: Secure form of HTTP used commonly for Internet business transactions or any time when a secure connection is required. Uses port 443.

Hub

Electronic device that sits at the center of a star topology network, providing a common point for the connection of network devices. Hubs repeat all information out to all ports and have been replaced by switches, although the term is still commonly used.

Hybrid

A network topology that combines features from multiple other topologies, such as the star-bus topology.

hyperthreading

CPU feature that enables a single pipeline to run more than one thread at once.

Hypervisor

Software that enables a single computer to run multiple operating systems simultaneously.

I/O

input/output: General term for reading and writing data to a computer. "Input" includes data entered from a keyboard, identified by a pointing device or loaded from a disk. "Output" includes writing information to a disk, viewing it on a CRT, or printing to a printer.

I/O Addressing

Using the address bus to talk to system devices.

IOAPIC

I/O advanced programmable interrupt controller: Typically located in the Southbridge, acts as the traffic cop for interrupt requests to the CPU.

I/O base address

First value in an I/O address range.

ICH

I/O Controller Hub: Official name for Southbridge chip found in Intel's chipsets.

icon

Small image or graphic, most commonly found on a system's desktop, that launches a program when selected.

ICS

Internet Connection Sharing: Windows feature that enables a single network connection to be shared among several machines. ICS was first introduced with Windows 98.

IDE

Integrated Drive Electronics: PC specification for small- to medium- sized hard drives in which the controlling electronics for the drive are part of the drive itself, speeding up transfer rates and leaving only a simple adapter. IDE only supported two drives per system of no more than 504 MB each, and has been completely supplanted by Enhanced IDE. EIDE supports four drives of over 8 GB each and more than doubles the transfer rate. The more common name for PATA drives.

IEC-320

Connects the cable supplying AC power from a wall outlet into the power supply.

IEEE

Institute of Electronic and Electrical Engineers: leading standards-setting group in the US

IEEE 1284

IEEE standard governing parallel communication

IEEE 1394

IEEE standard governing FireWire communication.

IEEE 1394a

Firewire standard that runs at 400 Mbps

IEEE 1394b

FireWire standard that runs at 800 Mbps.

IEEE 802.11

Wireless Ethernet standard more commonly known as Wi-Fi.

Image Deployment

Operating system installation that uses a complete image of a hard drive as an installation media. Helpful when installing an OS on a large number of identical PCs.

Image File

Bit-by-bit image of data to be burned on CD or DVD-from one file to an entire disc-stored as a single file on a hard drive. Particularly handy when copying from CD to CD or DVD to DVD.

Suspension of a process, such as the execution of a computer program, caused by an event external to the computer and performed in such a way that the process can be resumed. Events of this kind include sensors monitoring laboratory equipment or a user pressing an interrupt key.

iOS

The operating system of Apple mobile devices.

IP address

Numeric address of a computer connected to the internet. An IPv4 address is made up of four octets of 8-bit binary numbers translated into their shorthand numeric values. An IPv6 address is 128 bits long. The IP address can be broken down into a network ID and a host ID. Also called Internet address.

IPSec

Internet Protocol security: Microsoft's encryption method of choice for networks consisting of multiple networks linked by a private connection, providing transparent encryption between the server and the client.

IPv4

Internet Protocol version 4: Internet standard protocol that provides a common layer over dissimilar networks; used to move packet among host computers and through gateways if necessary. Part of the TCP/IP protocol suite. Uses the dotted-decimal format - xxx.xxx.xxx.xxx.

IPv6

Internet Protocol version 6: Protocol in which addresses consist of eight sets of four hexadecimal numbers, each number being a value between 0000 and FFFF, using a colon to separate the numbers.

IrDA

Infrared Data Association protocol: Protocol that enables communication through infrared devices, with speeds of up to 4 Mbps.

IRQ

Interrupt request: Signal from a hardware device, such as a modem or a mouse, indicating that it needs the CPU's attention. In PCs, IRQs are sent along specific IRQ channels associated with a particular device. IRQ conflicts were a common problem in the past when adding expansion boards, but the plug-and-play specification has removed this headache in most cases.

ISA

Industry Standard Architecture design was found in the original IBM PC for the slots that allowed additional hardware to be connected to the computer's motherboard. And 8-bit, 8.33 MHz expansion bus was designed by IBM for its AT computer and released to the public domain. An improved 16-bit bus was also released to the public domain. Replaced by PCI in the mid-90's.

ISDN

Integrated services digital network: CCITT standard that defines a digital method for communications to replace the current analog telephone system. ISDN is superior to POTS telephone lines because it supports a transfer rate of up to 128 Kbps for sending information from computer to computer. It also allows data and voice to share a common phone line.

ISO-9660

CD format to support PC file systems on CD media. supplanted by the Joliet format.

ISO file

Complete copy of a storage media device, typically used for optical discs.

Joliet

Extension of the ISO 9660 format. Most popular CD format to support PC file systems on CD media.

joule

Unit of energy describing how much energy a surge suppressor can handle before it fails.

Jump List

A Windows 7 menu that shows context-sensitive information about whatever is on the taskbar.

jumper

Pair of small pins that can be shorted with a shunt to configure many aspects of PCs. Often used in configurations that are rarely changed, such as master/slave settings on IDE drives.

Kerberos

Authentication encryption developed by MIT to enable multiple brands of servers to authenticate multiple brands of clients.

kernel

Core portion of program that resides in memory and performs the most essential operating system tasks.

Knowledge Base

Large collection of documents and FAQs that is maintained by Microsoft. Found on Microsoft's Web site, the Knowledge Base is an excellent place to search for assistance on most OS problems.

KVM

keyboard, video, mouse

LAN

Local area network: Group of PCs connected via cabling, radio, or infrared that use this connectivity to share resources such as printers and mass storage.

Laser printer

Electrophotographic printer in which a laser is used as the light source.

Latency

Amount of delay before a device may respond to a request; most commonly used in reference to RAM

LBA

Logical Block Addressing: Translation of IDE drives promoted by Western Digital as a standardized method for breaking the 504-MB limit in IDE drives. Subsequently universally adopted by the PC industry and now standard on all EIDE drives.

LCD

Liquid crystal display: Type of display commonly used on portable PCs. Also have mostly replaced CRTs as the display of choice for most desktop computer users, due in large part to rapidly falling prices and increasing quality. LCDs use liquid crystals and electricity to produce images on the screen.

LED

light-emitting diode: Solid-state device that vibrates at luminous frequencies when current is applied.

Level 1 cache

First RAM cache accessed by the CPU, which stores only the absolute most-accessed programming and data used by currently running threads. Always the smallest and fastest cache on the CPU.

Level 2 Cache

Second RAM cache accessed by the CPU. Much larger and often slower than the L1 cache, and accessed only if the requested program/data is not in the L1 cache.

Level 3 Cache

Third RAM cache accessed by the CPU. Much larger than the L1 and L2 caches, and accessed only if the requested program/data is not in the L2 cache. Seen only on high-end CPUs.

LDAP

Lightweight Directory Access Protocol: Protocol used by many operating systems and applications to access directories.

Live DVD

The Windows installation media, which loads the Windows Preinstallation Environment (WinPE) directly from disc into memory and doesn't access or modify the hard drive.

Local Security Policy

Windows tool used to set local security policies on an individual system.

log files

Files created in Windows to track the progress of certain processes.

logical drives

Sections of an extended partition on a hard drive that are formatted and assigned a drive letter, each of which is presented to the user as if it were a separate drive.

loopback plug

Device used during loopback tests to check the female connector on a NIC

Low-speed USB

USB standard that runs at 1.5 Mbps. Also called USB 1.1.

LPT Port

Commonly referred to as a printer port; usually associated with a local parallel port.

LPX

First slimline form factor; replaced by NLX form factor

Lumens

Unit of measure for amount of brightness on a projector or other light source.

MAC Address

Media Access Control: Unique 48-bit address assigned to each network card. IEEE assigns blocks of possible addresses to various NIC manufacturers to help ensure that the address is always unique. The Data Link layer of the OSI model uses MAC addresses for locating machines.

MAC Address filtering

Method of limiting wireless network access based on the physical, hard-wired address of the units' wireless NIC.

Machine Language

Binary instruction code that is understood by the CPU.

Maintenance kits

Set of commonly replaced printer components provided by many manufacturers

Matte

Laptop screen finish that offers a good balance between richness of colors and reflections, but washes out in bright light.

MBR

Master-Boot Record: Tiny bit of code that takes control of the boot process from the system BIOS

MCC

Memory Control Chip: Chip that handles memory requests from the CPU. Although once a special chip, it has been integrated into the chipset or CPU on modern PCs.

MCH

Memory Controller Hub: Intel-coined name for what is now commonly called the Northbridge.

md (mkdir) command

Command in the command-line interface used to create directories.

mega

Prefix that stands for the binary quantity 1,048,576 (2^20) or the decimal quantity of 1,000,000. One megabyte is 1,048,576 bytes. One megahertz, however, is a million hertz. Sometimes shortened to Meg, as in a "286 has an address space of 16 Megs.)

Megapixel

Term used typically in reference to digital cameras and their ability to capture data.

memory

Device or medium for temporary storage of programs and data during program execution. Synonymous with storage, although it most frequently refers to the internal storage of a computer that can be directly addressed by operating instructions. A computer's temporary storage capacity is measured in KB, MB, or GB of RAM. Long-term data storage on disks is also measured in KB, MB, GB, or TB.

Memory Addressing

Taking memory address from system RAM and using it to address nonsystem RAM or ROM so the CPU can access it.

Mesh Topology

Network topology where each computer has a dedicated line to every other computer, most often used in wireless networks.

MFT

Master File Table: Enhanced file allocation table used by NTFS.

MicroATX

Variation of the ATX form factor, which uses the ATX power supply. MicroATX motherboards are generally smaller than their ATX counterparts but retain all the same functionality.

microBTX

Variation of the BTX form factor, MicroBTX motherboards are generally smaller than their BTX counterparts but retain all the same functionality.

microdrive

Tiny hard drives using the CompactFlash form factor.

microprocessor

"Brain" of a computer. Primary computer chip that determines relative speed and capabilities of the computer. Also called CPU.

Musical Instrument Digital Interface: Interface between a computer and a device for simulating musical instruments. Rather than sending large sound samples, a computer can simply send "instructions" to the instrument describing pitch, tone, and duration of a sound. MIDI files are therefore very efficient. Because a MIDI file is made up of a set of instructions rather than a copy of the sound, modifying each component of the file is easy. Additionally, it is possible to program many channels, or "voices," of music to be played simultaneously, creating symphonic sound.

MIDI-enabled device

External device that enables you to input digital sound information in the MIDI format; for example, a MIDI keyboard (the piano kind).

migration

Moving users from one OS or hard drive to another

MIMO

Multiple in/multiple out: Feature of 802.11n devices that enables the simultaneous connection of up to four antennas, greatly increasing thoughput.

mini connector

One type of power connector from a PC power supply unit. Supplies 5 and 12 volts to peripherals. Also known as a floppy connector.

mini-DIN

Small connection most commonly used for keyboards and mice. Many modern systems implement USB in place of mini-DIN connections. Also called PS/2

Mini-ITX

The largest and the most popular of the three ITX form factors. At a minuscule 6.7 by 6.7 inches, Mini-ITX competes with microATX and proprietary small form factor (SFF) motherboards.

Mini-PCI

Specialized form of PCI designed for use in laptops.

Mini-PCIe

Specialized form of PCIe designed for use in laptops

mini power connector

Connector used to provide power to floppy disk drives.

mirror set

A type of mirrored volume created by Windows 7 Professional, Enterprise, and Ultimate editions.

Mirroring

Reading and writing data at the same time to two drives for fault tolerance purposes. Considered RAID level 1.

MMC

Microsoft Management Console: Means of managing a system, introduced by Microsoft with Windows 2000. The MMC allows an administrator to customize management tools by picking and choosing from a list of snap-ins. Available snap-ins include Device Manager, Users and Groups, and Computer Management.

MMX

Multimedia extensions: Specific CPU instructions that enable a CPU to handle many multimedia functions, such as digital signal processing. Introduced with the Pentium CPU, these instructions are used on all x86 CPUs.

mode

Any single combination of resolution and color depth set for a system.

Small circuit board that DRAM chips are attached to. Also known as a "stick."

Molex connector

Computer power connector used by optical drives, hard drives, and case fans. Keyed to prevent it from being inserted into a power port improperly.

monaural

Describes recording tracks from one source (microphone) as opposed to stereo, which uses two sources.

monitor

Screen that displays data from a PC. Can use either a cathode ray tube (CRT) or a liquid crystal display (LCD) to display images.

motherboard

Flat piece of circuit board that resides inside your computer case and has a number of connectors on it. Every device in a PC connects directly or indirectly to the motherboard, including CPU, RAM, hard drives, optical drives, keyboard, mouse, and video cards.

mount point

Drive that functions like a folder mounted into another drive.

move command

Command in the command-line interface used to move a file from one location to another.

MP3

Short for MPEG Audio Layer 3. MP3 is a type of compression used specifically for turning high-quality digital audio files into much smaller, yet similar sounding, files

MPA

Microsoft Product Activation: Introduced by Microsoft with the release of Windows XP, prevents unauthorized use of Microsoft's software by requiring users to activate the software.

MPEG-2

Moving Pictures Experts Group: Standard of video and audio compression offering resolutions up to 1280x720 at 60 frames per second.

Microsoft's variation of the CHAP protocol, which uses a slightly more advanced encryption protocol. Windows Vista uses MS-CHAP v2 (version 2), and does not support MS-CHAP v1.

msconfig

System Configuration Utility: Executable file that runs the Windows System Configuration utility, which enables users to configure a system's boot files and critical system files. Often used for the name of the utility, and in "just run msconfig."

Provides information about hardware resources, components, and the software environment. Also known as System Information.

Multiboot Installation

OS installation in which multiple operating systems are installed on a single machine. Can also refer to kicking a device several times in frustration.

Multicore Processing

Using two or more execution cores on one CPU die to divide up work independently of the OS.

multitasking

Process of running multiple programs or tasks on the same computer at the same time.

multitouch

Input method on many smartphones and tablets that enables you to use multiple fingers to do all sorts of fun things, such as using two fingers to scroll or swipe to another screen or desktop.

Nano-ITX

A 4.7 inch by 4.7 inch variation of the ITX form factor.

NAT

Network Address Translation: A means of translating a system's IP address into another IP address before sending it out to a larger network. NAT manifests itself by a NAT program that runs on a system or a router. A network using NAT provides the system on the network with private IP addresses. The system running the NAT software has two interfaces: one connected to the network and the other connected to the larger network.

The NAT program takes packets from the client systems bound for the larger network and translates their internal private IP addresses to its own public IP address, enabling many systems to share a single IP address.

native resolution

Resolution on an LCD monitor that matches the physical pixels on the screen. CRTs do not have fixed pixels and therefore do not have a native resolution.

net command

Command in Windows that allows users to view a network without knowing view a network without knowing the names of the other computers on the networks

NetBIOS

Network Basic Input/Output System: Protocol that operates at the Session layer of the OSI seven-layer model. This protocol creates and manages connections based on the names of the computers involved

NetBIOSEUI

Network Basic Input/Output System Extended User Interface: The default networking protocol for early versions of Windows.

NAS

Network attached storage: A device that attaches to a network for the sole purpose of storing and sharing files.

network ID

Number that identifies the network on which a device or machine exists. This number exists in both IP and IPX protocol suites.

network protocol

Software that takes the incoming data received by the network card, keeps it organized, sends it to the application that needs it, and then takes outgoing data from the application and hands it to the NIC to be sent out over the network.

network technology

A practical application of a topology and other critical standards to provide a method to get data from one computer to another on a network. It defines many aspects of a network, from the topology, to the frame type, to the cabling and connectors used.

NIC

Network Interface Card or controller: Expansion card or motherboard interface that enables a PC to connect to a network via a network cable. A wireless NIC enables connection via radio waves rather than a physical cable.

nit

Value used to measure the brightness of an LCD display. A typical LCD display has a brightness of between 100 and 400 nits.

NLQ

near-letter quality: Designation for dot-matrix printers that use 24-pin printheads.

NLX

Second form factor for slimline systems. Replaced the earlier LPX form factor. (NLX apparently stands for nothing; it's just a cool grouping of letters.)

NMI

non-maskable interrupt: Interrupt code sent to the processor that cannot be ignored. Typically manifested as a BSoD.